Experimental Characterization of the AFIT Neutron Facility.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
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AFITs Neutron Facility was characterized for room-return neutrons using a 252Cf source and a Bonner sphere spectrometer with three experimental models, the shadow shield, the Eisenhauer, Schwartz, and Johnson ESJ, and the polynomial models. The free-field fluences at one meter from the ESJ and polynomial models were compared to the equivalent value from the accepted experimental shadow shield model to determine the suitability of the models in the AFIT facility. The polynomial model behaved erratically, as expected, while the ESJ model compared to within 4.8 of the shadow shield model results for the four Bonner sphere calibration. The ratio of total fluence to free-field fluence at one meter for the ESJ model was then compared to the equivalent ratio obtained by a Monte Cario Neutron-Photon transport code MCNP, an accepted computational model. The ESJ model compared to within 6.2 of the MCNP results. AFITs fluence ratios were compared to equivalent ratios reported by three other neutron facilities which verified that AFITs results fit previously published trends based on room volumes. The ESJ model appeared adequate for health physics applications and was chosen was chosen for calibration of the AFIT facility. Neutron Detector, Bonner Sphere, Neutron Dosimetry, Room Characterization.
- Nuclear Physics and Elementary Particle Physics
- Weapons Effects (Biological)